This application claims the priority of German Patent Application No. 199 62 243.4, filed in Germany, Dec. 22, 1999, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a driving position selector with an emergency release for a parking position of an automatic transmission of an automobile, with the driving position selector for selecting at least the driving steps of the automatic transmission, xe2x80x9cDxe2x80x9d, xe2x80x9cNxe2x80x9d, xe2x80x9cRxe2x80x9d, xe2x80x9cPxe2x80x9d of an automobile, which are selected by the driver over a control device and engaged by electro-hydraulic setting elements activated by a transmission control device, it being possible to disengage a parking position, engaged in the xe2x80x9cPxe2x80x9d driving position, by a release device in the automatic transmission housing, which can be activated by the driver over an operating device, especially a hand lever, for which reason the operating device is connected by a Bowden cable with a release lever of the release device and the release lever is mounted firmly on an axis, which is rotated back and forth by the electro-hydraulic setting elements when the parking position is engaged and disengaged and, with that, swivels the release lever forward and backward.
The operating range of an automatic transmission is divided into different manually selectable operating positions, which are referred to as driving positions. The concept of driving positions, as used here, includes all driving positions of an automatic transmission, and also the parking position and the neutral position.
It is already known that the driving positions of an automatic transmission of a motor vehicle, selected by the driver at a control device, can be engaged by electro-hydraulic setting elements, which are activated by a transmission control device.
German Patent Document DE 4422257 C1 describes a driving position selector for an automatic transmission, for which the parking position is selected automatically after the ignition is switched off. In order to be able to tow the vehicle when the driving position selector fails to function and the parking position is engaged, it is described that the parking position can be disengaged by the driver by an emergency release, which can be operated by the driver. This emergency release is constructed as an operative connection, such as a Bowden cable, between a manual lever, which can the operated by a driver, and a release device for the parking position.
For this parking position emergency release, a mechanical connection, such as a Bowden cable, is required between the control device and the release device in the transmission.
It is an object of the invention, to make available a driving position selector with an emergency release for the parking position of an automatic transmission, for which the control device no longer has a mechanical connection with the release device in the transmission and is constructed simply.
This objective is achieved according to preferred embodiments of the invention, by providing that the swiveling motion of the release lever is not transferred to the Bowden traction cord, since the release lever can move along a Bowden traction cord suspended in the release lever, because positive locking between the Bowden traction cord and the release lever over a thickening of the Bowden traction cord can be attained only if the operating device is activated. Further advantageous developments of preferred embodiments of the invention are set forth in the following description and the claims.
Pursuant to the invention, a driving position selector is provided for selecting at least the operating positions of the automatic transmission, xe2x80x9cDxe2x80x9d, xe2x80x9cNxe2x80x9d, xe2x80x9cRxe2x80x9d, xe2x80x9cPxe2x80x9d (of an automobile), which are selected by the driver over a control device and engaged by electro-hydraulic setting elements activated by a transmission control device. It is possible to disengage a parking position, engaged in the xe2x80x9cPxe2x80x9d driving position, by a release device in the automatic transmission housing, which can be activated by the driver over an operating device, especially a hand lever, for which reason the operating device is connected by a Bowden cable to a release lever of the release device. The release lever is mounted firmly on an axis, which is rotated forward and backward when the parking position is engaged and disengaged by the electro-hydraulic setting elements. With that, the axis swivels the release lever back and forth. Since the release lever can move along a Bowden traction cord suspended in the release lever, the swiveling motion of the release lever is not transferred to the Bowden cable because positive locking between the Bowden traction cord and the release lever over a thickening of the Bowden traction cord can be attained only if the operating device is activated.
Such a configuration of an emergency release of the parking position advantageously operates with few components and can be integrated simply in many vehicle designs.
A preferred embodiment of the invention is characterized in that a bracket is constructed at the release lever, through which the Bowden traction cord extends and that, as seen from the release lever, the operating device is mounted on one side of the Bowden traction cord and the thickening is mounted on the other side and is configured so that it cannot be pulled through the bracket.
This has the advantage that the individual parts of the emergency release of the parking position are constructed very simply and can be installed easily.
A further preferred embodiment of the invention is characterized in that the thickening of the Bowden traction cord is produced at a place, which is at such a distance from the release lever, that it is possible for the release lever to carry out its rotational movement with the axis, when the parking position is engaged and disengaged by the electro-hydraulic setting elements. However, when the parking position is engaged, the thickening of the Bowden traction cord comes into contact with the release lever when the activating device is activated and as a result, the parking position is bought from its engaged position into its disengaged position.
This is one embodiment of the invention, which furthermore can be installed quickly and is not very interference prone.
A preferred example of the invention is described in the following in conjunction with the associated drawing.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.